Authors:S. Aggarwal, D. Alamelu, P. Khodade, and P. Shah
Determination of 238Pu in plutonium bearing fuels is required as a part of the chemical quality assurance of nuclear fuels. In addition, the determination
of 238Pu is required in nuclear technology for many other applications, e.g., for developing isotope correlations and while using
238Pu as a spike (tracer) in isotope dilution α-spectrometry (IDAS). This determination usually involves the use of α-spectrometry on purified Pu sample. In view of the random errors associated with the counting statistics and the systematic
errors due to (1) in-growth of 241Am in purified Pu sample and (2) tail contribution correction methodology in α-spectrometry, the precision and accuracy obtainable by α-spectrometry are limited. Thermal ionization mass spectrometry (TIMS) is generally used for the determination of different
Pu isotopes other than 238Pu. This is due to the ubiquitous isobaric interference from 238U at 238Pu in TIMS. Recently, we have carried out studies on the formation of atomic and oxide ions of U and Pu by TIMS and developed
a novel approach using interfering element correction methodology to account for the isobaric interference of 238U at 238Pu in TIMS. This methodology is based on the addition of 235U (enrichment >90 atom%) to Pu sample followed by the determination of 238U/235U atom ratio using UO+ ion and determination of Pu isotope ratios using Pu+ ion, from the same filament loading. The TIMS methodology was used for the determination of 238Pu in different Pu samples in U based nuclear fuels from PHWRs with 238Pu content about 0.2 atom%. The 238Pu determination was also carried out using α-spectrometry. This paper reports the results obtained by the two methods and presents the ments and shortcomings of the two
Authors:K. Ramakumar, P. Khodade, A. Parab, S. Chitambar, and H. Jain
Application of dicesium metaborate ion /Cs2BO
/ in Thermal Ionisation Mass Spectrometry /TIMS/ for the determination of boron present at sub ppm level in heavy water moderator as well as for the isotopic composition of boron in boron carbide is reported. Contamination of samples with natural boron while determining trace levels of boron in heavy water was checked by analysing SRM-952 isotopic reference material. The atom ratios of boron in B4C were determined by directly fusing the material on the tantalum filament with Cs2CO3 as well as with Na2CO3 and also by following the conventional fusion procedures and the results were compared.
Authors:K. Ramakumar, A. Parab, P. Khodade, A. Almaula, S. Chitambar, and H. Jain
Investigations were carried out on the determination of isotopic composition of boron using Cs2BO
ion and thermal ionisation mass spectrometry. The results show distinct advantage over the normally used Na2BO
Authors:S. Aggarwal, A. Almaula, P. Khodade, A. Parab, R. Duggal, C. Singh, A. Rawat, G. Chourasiya, S. Chitambar, and H. Jain
K-factors (= certified isotope ratio/observed isotope ratio) are determined for the isotope abundance measurements of uranium and plutonium by thermal ionisation mass spectrometry. An mdf of 0.07% and 0.18% per mass unit differing by a factor of about 3, is obtained for uranium and plutonium, respectively, employing double rhenium filament assembly in the ion source and Faraday cup as the detector using the presently available isotopic reference materials of uranium and plutonium.